Improvement in envelopes



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UNIT D STATES PATENT FFIGE.

GEORGE H. BOOTH, OF RATHMINES, DUBLIN, GREAT BRITAIN.

IMPROVEMENT IN ENVELOPES.

Specification forming part of Letters Patent No. 182,550, dated September 26, 1876; application filed April 3, 1876.

To all whom it may concern:

Be it known thatI, GEORGE HENRY Boo'rn, of Rathmines, Dublin, Kingdom of Great Britain and Ireland, have invented new and useful Improvements in the Manufacture of Envelopes, which invention is fully set forth in the annexed specification, reference being had to the accompanying drawings.

This invention ofimprovementsin the manufacture of envelopes has for its object to produce an envelope wherein letters, remittances, or other things may be sent through the post or otherwise with greater safety than heretofore, said envelope being expressly designed not only to securely hold its contents, but also to render tamperingimpossible with out leaving such indications as shall render it apparent even to the most casual observer that improper attempts have been made to gain access to the contents of the envelope.

Figure l of the drawings represents a blank cut to form one of my improved envelopes. Fig. 2 shows the completed envelope.

I form in one piece of paper or other suitable material, Fig. l, the front A of the envelope, a top flap, B, whose sides run for some distance almost in line with those of the body of the envelope, a bottom flap or back, 0, of nearly equal width and depth to the ultimate width and depth of the finished envelope, Fig. 2, and having in it the cuts or slits O 0* G and two narrow side flaps, D, one of which may be perforated at D. I coatwith the under-mentioned or analogous composition, or with ordinary gum, as shown at B, so much of the inner surface of the top flap as will, when the envelope is closed, cover the two slits G and the intermediate part of the bottom flap, and I also coat in likemanner the entire inner surfaces of the two side flaps D, with the exception of a small portion on the one side flap from the perforations D downward when those perforations are adopted. The compo sition I prefer to use consists of five ounces of shellac, one ounce of borax, and one ounce of alum, boiled in one pint of water until completely dissolved. Upon the coating of this composition I afterward place a coating of ordinary gum in the ordinary manner, to give additional security, and I fold the two side flaps D over, and cause them to firmlyadhere throughout their entire areas (with the exception of the above-described portion) to the bottom flap O, which, in my improved envelope, is in reality no longer a flap, but constitutes a strong entire back onto which the top flap B, when closed, is almost ihroughout its entire surface caused to adhere with great tenacity.

In a modified form of myimproved envelope I coat almost the entire surface of the top flap with the hereinbefore-described adhesive composition or ordinary gum. In this form of envelope I omit the slits G The slits in the bottom flap are for the purpose of rendering impossible unobserved tam- I pering' by the introduction of any instrument underneath. It will be obvious that if any instrument be inserted between the top and side flaps it will make its way underneath the bottom flap through the slits G 0*, and, in like manner, any instrument introduced between the side and bottom flaps will enter the slits 0 thus in either case the instrument used will cause the bottom flap to tear, and thus show that attempts have been made to open the envelope. The slits G 0 being on the flap which comes underneath when the envelope is scaled, cannot be seen. When slits or analogous devices are on the outer flap, so that they can be seen, an operator, by skillfully inclining the device by which he seeks to separate the flaps, is more likely to succeeed in surreptitiously opening the envelope. I attach much importance to the fact that the slits are on the under flap, and I also attach importance to the fact that the slits are formed with bends 0*, projecting laterally from the inner ends of the slits, so that in an attempt to roll the penholder or the-like between the flaps, to separate them, it will move some distance after the separation has ceased before the paper begins to tear. This condition avoids the possibility of the operator lifting the paper and dividing the flaps by any amount of care.

I am aware that envelopes have been made in various ways with top flaps, bottom flaps, and side flaps, and to this I lay no general claim, my invention being confined to the improved manufacture of envelopes above described and shown, by which greatly-increased strength and security are attained, in conjunction with considerable economy in paper, and the number of flaps available for tampering' with is reduced.

I claim 1. As a new article of manufacture, an envelope composed of a front, A, formed in one with a top flap, B, two side flaps, D, and a bottom flap, 0, formed with slits O (3*, the said flaps being coated with compositiomand folded over in the manner and forthe purpose hereinbefore described and set forth.

2. The combination, with the front A, top flap B, and the bottom flap 0, formed with slits C of the two side flaps, one being perforated with holes D, and almost the entire inner surfaces of the top flap and solid side flap, and one solid portion only (down to the perforations D) of the perforated side flap being coated with adhesive composition, as hereinbefore described, so that the whole may be folded up to-form a safety-envelope, substantially as herein set forth, for the purpose specified.

GEORGE HENRY BOOTH. 

